# Obtaining momentum distibution from Green's functions

• Emman1
In summary, the conversation discusses obtaining the momentum distribution (n_k) from the Green functions, specifically in the context of electron correlation in a 2-D Hubbard model. The speaker is seeking advice on how to calculate and plot the Green functions, potentially using software such as Matlab.
Emman1
How does one obtain the momentum distribution (n_k) from the green functions Is there a software for it if so where can I get it
Thanks
Emman1

Momentum of what, in which system and under what conditions?

Does this help?

http://www2.fz-juelich.de/nic-series/volume31/mavropoulos.pdf

Last edited by a moderator:
I am working on electron correlation in an 8 X8(64 site) square lattice at half filling using the 2-D Hubbard model. using quantum monte Carlo I was able to obtain the Green functions. To get the momentum distribution I am required to calculate the Fourier transform of the Green function. The problem is I do not know how to go about calculating the Green functions and plotting it. Can it be done with Matlab?

## 1. What is momentum distribution?

Momentum distribution is a measure of the distribution of momentum states within a system, providing information about the movement and behavior of particles within that system.

## 2. What are Green's functions?

Green's functions are mathematical tools used in quantum mechanics to describe the relationship between the state of a quantum system and the state of its environment.

## 3. How are momentum distributions obtained from Green's functions?

Momentum distributions can be obtained from Green's functions through a mathematical process known as Fourier transformation. This involves converting the Green's function from a time domain to a momentum domain, allowing for the calculation of the momentum distribution.

## 4. What is the significance of obtaining momentum distributions from Green's functions?

Obtaining momentum distributions from Green's functions allows for the analysis and understanding of the behavior and interactions of particles within a quantum system. This information is crucial in many areas of physics, such as condensed matter physics and quantum field theory.

## 5. Are there any limitations to obtaining momentum distributions from Green's functions?

While Green's functions are a powerful tool for understanding quantum systems, there are limitations to obtaining momentum distributions from them. These limitations primarily arise from the complexity and nonlinearity of many quantum systems, making the calculation and interpretation of momentum distributions challenging.

Replies
1
Views
1K
Replies
2
Views
2K
Replies
3
Views
955
Replies
1
Views
926
Replies
9
Views
1K
Replies
7
Views
2K
Replies
2
Views
2K
Replies
20
Views
6K
Replies
1
Views
1K
Replies
5
Views
758